Graphene is a one-atom-thick planar sheet of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. It can be viewed as an atomic-scale chicken wire made of carbon atoms and their bonds. Graphene exhibits new types of fundamental physical properties not found in other materials. From a device point of view the most interesting are the high charge carrier mobility with ballistic transport, high current density, high thermal conductivity, and the possibility to control the electrical properties. In 2004, single graphene sheets, truly two-dimensional atomic thick carbon crystals, were verifiably isolated by mechanical exfoliation of graphite bulk. It has recently been discovered that graphene sheets may be fabricated. These graphene sheets are good conductors, for example about 20 times that of silicon MOSFETs.
Nanowire networks made for example of carbon nanotubes, or silicon nanowires have been studied for a number of years. However, these networks have rather low conductivity, due to high resistance wire-to-wire connections within the network.